The present invention relates to a method of manufacturing a blasting device to be used to introduce a gas and/or solid material into a metallurgical vessel, particularly a convertor, the device including a ceramic blasting brick with metallic blasting tubes pressed or embedded therein, the ends of the tubes at the base of the brick being secured to a metallic or metal apertured plate. The invention also relates to a blasting device manufactured in accordance with such method.
Blasting devices of this type serve, as is known, to supply gases and/or solid materials to a metal melt situated within the metallurgical vessel.
Such a blasting device is described in U.S. Pat. No. 4,539,043 for a convertor base. A blasting device of the same type is also known for an electric furnace from Radex-Rundschau, Volume 1, 1990, pages 195 to 202. In both cases the metallic blasting tubes are pressed or embedded into the ceramic material of the blasting brick which, as is known, is pressed with a very high volumetric compression ratio. This has the result that, after the pressing process, the positions of the metallic blasting tubes in the blasting brick frequently differ substantially from the installed positions originally provided. The function of the blasting brick is, on the one hand, thereby impaired to a considerable extent. On the other hand, however, difficulties also arise in the completion of the blasting brick since it is practically impossible due to the differing installed positions of the blasting tubes to use a prefabricated apertured plate with defined tube connection points. In the known gas and/or solid material blasting devices of the type referred to above, it is, therefore, in practice often necessary to adapt the apertured plate to the final installed positions of the blasting tubes and to secure such tubes subsequently to the apertured plate, whereby in practice only expensive welded connections ensure the necessary seal of the tube connecting and fastening points.